• The Journal of Engineering Geology
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• v.30 no.4
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• pp.469-483
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• 2020

The results of long-term groundwater level and quality monitoring can be used not only as the basic data for evaluating the impact of various disasters including climate change and establishing responses, but also as key data for predicting and managing geological disasters such as earthquakes. Some countries use groundwater level and quality monitoring for researches to predict earthquakes and to assess the impacts of the earthquake disaster. However, a few cases in Korea report on individual groundwater quality factors (i.e., dissolved ions) observed before and after the earthquakes, being different from other countries. To establish the abnormality criteria for groundwater quality in Pohang, groundwater samples were collected and analyzed five times from 14 agricultural or private wells existing in Shingwang-myeon and Heunghae-eup. As a result of the analysis, it was found that Ca2+ was the dominant cation in Shingwang-myeon, while Na+ was the dominant cation in Heunghae-eup. The elevated NO3- concentration in Shingwang-myeon is contributed to the agricultural activity in the area. A high concentration of Fe was detected in a well on Heunghae-eup; the concentration exceeded the drinking water standard by nearly 100 times. Relatively higher dissolved ions were observed in the groundwater of Heunghae-eup, and it is considered as the result of the flow velocity difference and water-rock reaction accompanying the difference in bedrock and sediment characteristics. The groundwater of Shingwang-myeon appeared to be most affected by the weathering of granite and silicates, while that of Heunghae-eup was mainly affected by the weathering of silicates and carbonate. The background concentrations (baselines) of groundwater Shingwang-myeon and Heunghae-eup was identified through the survey; however, the continuous monitoring is required to monitor the possible changes and the repeatability of seasonal variation.

• Korean Journal of Environmental Agriculture
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• v.40 no.4
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• pp.248-259
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• 2021

BACKGROUND: Contaminated water was a major source of food-borne pathogens in various recent fresh produce-related outbreaks. This study was conducted to investigate the microbial contamination level and correlations between the level of sanitary indicator bacteria and the detection ratio of pathogens in agricultural water by logistic regression analysis. METHODS AND RESULTS: Agricultural water was collected from 457 sites including surface water (n=300 sites) and groundwater (n=157 sites) in South Korea from 2018 to 2020. Sanitary indicator bacteria (total coliform, fecal coliform, and Escherichia coli) and food-borne pathogens (pathogenic E. coli, E. coli O157:H7, Salmonella spp., and Listeria monocytogenes) were analyzed. In surface water, the coliform, fecal coliform, and E. coli were 3.27±0.89 log CFU/100 mL, 1.90±1.19 log CFU/100 mL, and 1.39±1.26 log CFU/100 mL, respectively. For groundwater, three kinds of sanitary indicators ranged in the level from 0.09 - 0.57 log CFU/100 mL. Pathogenic E. coli, Salmonella and Listeria monocytogenes were detected from 3%-site, 1.5%- site, and 0.6%-site water samples, respectively. According to the results of correlations between the level of sanitary indicator bacteria and the detection ratio of pathogens by logistic regression analysis, the probability of pathogen detection increased individually by 1.45 and 1.34 times as each total coliform and E. coli concentration increased by 1 log CFU/100mL. The accuracy of the model was 70.4%, and sensitivity and specificity were 81.5% and 51.7%, respectively. CONCLUSION(S): The results indicate the need to manage the microbial risk of agricultural water to enhance the safety of fresh produce. In addition, logistic regression analysis is useful to analyze the correlation between the level of sanitary indicator bacteria and the detection ratio of pathogens in agricultural water.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.984-993
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• 1993

land application of sewage sludge requires careful monitoring because of its potential for contamination of surface water and groundwater. A rainfall simulator was used to investigated the effects of freshly applied sludge on runoff of sediment and nutrients from agricultural crop lands. Rain was applied to 16 experimental field plots. A three run sequence was used to simulate different initial moisture conditions. Runoff, sediment and nutrient losses were monitored at the base of each plot during the simulated rainfall events. Sludge was surface applied and incorporated at conventionally -tilled plots and surface applied at no-till plots, at rates of 0, 75, 150 kg-N/ha. No-till practices greatly reduced runoff, sediment , and nutrient losses form the sludge treated plots, relative to the conventional tillage practices. Incorporation of the sludge was effective in reducing nutrient yields at the conventionally-tilled plots. This effect was more pronounced during the third rain torm, with wet initial conditions. Peak loadings of nutrients appeared during the rainstorm with wet initial conditions.

• Journal of Environmental Policy
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• v.4 no.2
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• pp.57-82
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• 2005

In this study, we propose methods for. the efficient management and integrity of groundwater in response to a diminishing supply. As an alternative water resource for the future. we investigated and comparatively analyzed the quality standards of groundwater in the US (New York, Wisconsin and Texas), Austria, Netherlands, Canada, Japan and United Kingdom. These developed countries heavily depend on groundwater, more than 70%, for drinking water and apply those drinking water standards to groundwater quality. However, there exists few differences in the quality standards of groundwater among the countries, because each country possesses its own individual environment and management. In Korea, surface water pollution is getting serious and its water resources are diminishing. Therefore we propose several new quality criteria that many countries regulate at these days for their efficient management of groundwater. There is a need to divide BTEX criterion into Benzene, Toluene, Ethylbenzene and Xylene, individually. In. addition, it is needed to establish BTEX criteria into agricultural water and industrial water use standards as well as daily life use standards. Also, regulations for some PAHs, showing carcinogenicity, are required. Due to rapid industrialization various hazardous chemicals were utilized and their uses are increasing each year. Therefore, there is a strong need to introduce n~w standards and tighter regulations of the levels. At the same time, the criterion of nitrogenous compounds need' to be regulated individually in order to prevent the damage incurred by the compounds. Several developed countries have established standards for radon, previously caused environmental accidents in Korea. Therefore, we propose the necessity of groundwater quality standards for radon in this study.

• Journal of Environmental Policy
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• v.10 no.1
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• pp.49-70
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• 2011

The numerous efforts have been made in understanding generation and transportation mechanism of nonpoint source pollutants from agricultural areas. Also, the water quality degradation has been exacerbated over the years in many parts of Korea as well as other countries. Nonpoint source pollutants are transported into waterbodies with direct runoff and baseflow. It has been generally thought that groundwater quality is not that severe compared with surface water quality. However its impacts on groundwater in the vicinity of stream quality is not negligible in agricultural areas. The SWAT model has been widely used in hydrology and water quality studies worldwide because of its flexibilities and accuracies. The spatial property of each HRU, which is the basic computational element, is not presented. Thus, the SWAT HRU mapping module was developed in this study and was applied to the study watershed to evaluate recharge rate and $NO_3-N$ loads in groundwater. The $NO_3-N$ loads in groundwater on agricultural fields were higher than on forests because of commercial fertilizers and manure applied in agricultural fields. The $NO_3-N$ loads were different among various crops because of differences in crop nutrient uptake, amount of fertilizer applied, soil properties in the field. As shown in this study, the SWAT HRU mapping module can be efficiently used to evaluate the pollutant contribution via baseflow in agricultural watershed.

• Korean Journal of Environmental Agriculture
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• v.39 no.4
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• pp.343-351
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• 2020

BACKGROUND: Irrigation water is known to be one of the major sources of bacterial contamination in agricultural products. In addition, anti-microbial resistance (AMR) bacteria in food products possess serious threat to humans. This study was aimed at investigating the prevalence of foodborne bacteria in irrigation water and evaluating their anti-microbial susceptibility. METHODS AND RESULTS: Surface water (n = 66 sites) and groundwater (n = 40 sites) samples were collected from the Gyeongi and Gangwon provinces of South Korea during April, July, and October 2019. To evaluate the safety of water, fecal indicators (Escherichia coli) and foodborne pathogens (E. coli O157:H7, Salmonella spp., and Listeria monocytogenes) were examined. E. coli isolates from water were further tested for antimicrobial susceptibility using VITEK2 system. Overall, detection rate of foodborne pathogens in July was highest among three months. The prevalence of pathogenic E. coli (24%), Salmonella (3%), and L. monocytogenes (3%) was higher in surface water, while only one ground water site was contained with pathogenic E. coli (2.5%). Of the 343 E. coli isolates, 22.7% isolates were resistant to one or more antimicrobials (ampicillin (18.7%), trimethoprim-sulfamethoxazole (7.0%), and ciprofloxacin (6.7%)). CONCLUSION: To enhance the safety of agricultural products, it is necessary to frequently monitor the microbial quality of water.

• Journal of Environmental Science International
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• v.29 no.4
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• pp.325-337
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• 2020

The purpose of this study was to analyze the soil environment of urban neighborhood parks and to use them as basic data for evaluating the ecological functions of urban parks such as groundwater regeneration, flood control, microclimate regulation, adsorption and purification. The landscape design criteria were generally evaluated as advanced, and further monitoring and studies are needed to evaluate the various ecological functions. It is also necessary to improve the phosphoric acid and nitrogen contents, which tended to be low. In addition, continuous monitoring is needed to assess the proper soil environment according to the biological species, and to evaluate the ecological functions. The results of this study can be used to evaluate the groundwater recharge of urban parks. In particular, when the land of the neighboring park is used for various purposes, the level of access of the user may be increased. Therefore, factors that may adversely affect the user's health, such as heavy metals and organic matters, should be selected and selected as management criteria. In addition, follow-up studies considering fertilization standards suitable for trees and growth of introduced vegetation, etc. are needed urgently to improve the soil environment.

• Journal of Environmental Science International
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• v.22 no.5
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• pp.625-638
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• 2013

Recently, the occurrences of droughts have been increased because of global warming and climate change. Water resources that mostly rely on groundwater are particularly vulnerable to the impact of precipitation variation, one of the major elements of climate change, are very sensitive to changes in the seasonal distribution as well as the average annual change in the viewpoint of agricultural activity. In this study, the status of drought for the present and future on Jeju Island which entirely rely on groundwater using SPI and PDSI were analyzed considering regional distribution of crops in terms of land use and fluctuation of water demand. The results showed that the precipitation distribution in Jeju Island is changed in intensity as well as seasonal variation of extreme events and the amount increase of precipitation during the dry season in the spring and fall indicated that agricultural water demand and supply policies would be considered by regional characteristics, especially the western region with largest market garden crops. Regarding the simulated future drought, the drought would be mitigated in the SPI method because of considering total rainfall only excluding intensity variation, while more intensified in the PDSI because it considers the evapotranspiration as well as rainfall as time passed. Moreover, the drought in the northern and western regions is getting worse than in the southern region so that the establishment of regional customized policies for water supply in Jeju Island is needed.

• Journal of Environmental Science International
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• v.8 no.6
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• pp.685-690
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• 1999

The pollution characteristics of groundwaters in Taegu City and correlation coefficients(r) between water pollution indicators were investigated for two years from January 1996 to December 1997. Volatile organic compounds such as TCE(tri-chloroethylene), PCE(tetrachloroethylene), l,l,l-trichloroethane, THM(trihalo-methane), dichloromethane, pesticides such as diazinon, parathion, malathion, and toxic inoganic matters such as As, Hg, Se, Pb, Cd, $Cr_6^+,$ CN were not detected in the groundwaters. Mean values of groundwater pollution indicators were below drinking-water standards, but hardness, $KMnO_4-C(potassium$ permanganate consumption), evaporate residues, $SO_4^{-2},\;Fe,\;NO_3^{-}-N,$ color and turbidity exceeded a little in some samples. As groundwater became deeper, hardness and evaporate residues remarkably increased, but $KMnO_4-C,\;NO_3^{-}-N,\;Cl-,$ color, turbity and bacteria decreased. $KMnO_4-C,$ evaporate residues, $Cl^-\;and\;SO_4^{-2}$ were very high at industrial and commercial areas, and $NO_3^--N$ and $NH_4^+-N$ were very high at agricultural and forest areas. It showed high positive significances in the relationships between hardness and each of evaporate residues, $SO_4^{-2}$, Zn and Mn, $KMnO_4-C$ and each of color, turbidity and Zn, color and each of turbidity, Cu, Zn and Mn, turbidity and each of Fe, Cu, Zn and Mn, and evaporate residues and each of $Cl^-,\;SO_4^{-2}$ and Zn.

• Journal of Soil and Groundwater Environment
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• v.23 no.3
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• pp.27-42
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• 2018

It is important to identify the contaminant sources and to evaluate the fate and transport of heavy metals to crops in agricultural lands. This study was conducted to evaluate metal sources and its transfer and accumulation to crop in agricultural soils. Pollution indices were calculated and multivariate analysis was performed to identify metal sources. To evaluate transfer and accumulation of metals to crops, the contents of phytoavailable metals were evaluated by using single extraction method and the correlation between metal content and soil properties was analyzed. Also the BCF was quantitatively evaluated for investigating the metal transition to each crop grown in the research area. As a result, Cr, Ni, and Co were expected to be mainly derived from geologic factors due to weathering of certain parent rocks. The content of nickel in soils of the research area was slightly higher than that of the concern level criteria based on total concentration, but the amount transferred and accumulated in the crops was actually low. Understanding the contamination characteristics by investigating the pollution sources of heavy metals and its transfer and accumulation to crops through various evaluation techniques could provide important information for proper management of the agricultural land.